In a growing fetus, the neural tube forms and develops into the central nervous system. It usually closes 25 to 27 days after conception. An incomplete closure of the neural tube is among the leading causes of malformations of the nervous system in newborns.
Although several factors may be responsible for this type of birth defect, the specific cause remains unknown. In most cases, these birth defects occur in families where both parents are in good health and do not have any specific health problems. Certain conditions in the mother however, may increase the risk of neural tube defects. They include:
- Vitamin B12 deficiency
- Use of antiepileptic drugs
- Having insulin-dependent diabetes
For couples who have had a baby with a neural tube defect, the risk of having another baby with a neural tube defect is 2 to 5%.
Types of neural tube defects
Anencephaly (absence of the brain): Occurs when the head end of the neural tube fails to close properly. Affected fetuses are not usually carried to term or die at birth.
Spina bifida: The defect involves the incomplete closure of the spine. Related problems are determined by the size and exact location of the defect.
Screening tests only help determine a child's risk of being born with spina bifida. Tests include an ultrasound and blood tests during the 2nd trimester.
Complications associated with neural tube defects are many and varied, but can also be nonexistent. Here are a few examples of some of the potential complications:
- Paralysis of the lower limbs
- Fecal or urinary incontinence
- Epileptic seizures
- Intellectual disability
Folic acid is a B vitamin that is vital to the development of the central nervous system, and is particularly important during the first month of pregnancy. Taking a minimum of 0.4 mg of folic acid helps reduce the risk of having a child with a neural tube defect. Since neural tube defects occur very early on in pregnancy, when most women do not even realize they are pregnant, it is recommended that women start taking folic acid before becoming pregnant.
Women who have an increased risk of giving birth to children with birth defects should consult a physician to determine the amount of folic acid that is right for them.
Currently, there is no cure for spina bifida. However, there are several types of surgery that can reduce the severity of certain complications.
If you have any questions, do not hesitate to speak to your pharmacist.